Drying apparatus



April 21, 1925.

J. G. COFFIN DRYING APPARATUS Filed April 30 1923 4 Sheets-Sheet l April21, 1925.

J. G. COFFIN DRYING APPARATUS Filed April 30. 1923 4Sheets-Sheet 2 a a W/e I/ 7 5 6 .V 5 .I 6 r0 6 1 7 l 7 a 7 W 6 0 m 7 avwemtoz JOSEPH G.COFFIN April 21, 1925: 1,534,030

' J. G. COFFIN DRYING APPARATUS Filed Apr so; 1923 4 Sheets-Sheet 5avwentoz 7 JOSEPH G-COFFIN Z i April 21, 1925.

J. G. COFFIN DRYING APPARATUS 4 Sheets-Sheet 4 Filed April 30, 1923Patented Apr. 21, 1925.

UNITED STATES JOSEPH G. GOFFIN', 0'1 HEMPSTEAD, NEW YORK, ASSIGINOR TOTHE G it atiana I nunnm COMPANY, OF NEW YORK, N. Y., A CORPORATION OFNEW JERSEY.

DRYING APPARATUS.

Application filed April 30, 1923. Serial No. 635,535.

rubber is made from latex obtained from cultivated trees, and theordinary method employed for obtaining the crude rubber from the latexis to coagulate the latter by some-material such as acetic acid, thecoagulated latex then being dried, and otherwise prepared for themarket. Methods and apparatus have been devised for obtaining rubberfrom the latex by finely dividing the latter and drying the particleswhile in suspension in a drying medium, the precipitated andagglomerated dried particles being then compacted to form crude rubber.Patent to Bradley & Cofiin, No. 1,428,526, dated September 12, 1922, isfor a method and apparatus for obtaining dried rubberlatex or similarmaterials in this manner, and the present invention aims generally toprovide improvements over the above-mentioned apparatus by which thecapacity may be increased, and economy,

' an improved product, and protection of the operatives from excessiveheat may be obtamed.

An object of the invention is to provide a latex drying apparatuscapable of continuous operation.

Another object is to provide an improved means for collecting andremoving the dried' latex from the d ing chamber. Still another 0 jectis to provide an improved form of drying chamber.

A further object is to provide means forprotecting the operative fromheat effects during removal of the dried product, during an interchangeof parts, and generally durmg the operation of the device.

Still another object is to provide an improved exhaust apparatus for thedrying medium b which the carrying oil of dried.

latex articles is substantially prevented.

St' another object is to provide a means ,for readily exchanging thelatex comminuting device when desired.

.For a detailed disclosure of the nature and objects of the invention,reference is had to the accompanying specification and drawings in whichlatter:

Fig. 1 is a plan view partially in section of the drier,

Fig. 2 is an elevation partially in section with parts omitted for thesake of clearness,

Fig. 3 is an enlarged sectional detail illustrating the exhaust andcollecting means for the drying medium,

Fig. 4 is 21 dia ammatic view illustrat-. ing the construction of themovable dried latex collecting platform and one form of mechanism formoving it, i

Fig. 5 is an enlarged sectional detail illustrating the mechanism forquickly exchangmg the spray unit and for protecting the operative duringsuch exchange,

Fig. 6 is a detail of a closure used, and

Fig. 7 is a detail of the mechanism removing the spray unit.

Referring to Figs. 1 and 2, the numeral 1 designates the drying chambergenerally, the latter being formed with side walls 2 tapering to the toi 3. In the present instance the side waiis and top are shown as made ofreinforced concrete on account of its permanence, weather resisting andnatural heat insulating qualities and its air tightness, but any othersuitable material may be used. As the greatest heat is developedadjacent the upper portion of the drying chamber and the drying islargely completed there the lower portion of the wall 2 may, if desired,be made entirely of the reinforced concrete, but the upper ortion ispreferably formed with a heat insulating layer 4 of the material knownas celite, or any other suitable material, the latter being cove-redwith a layer 5 of hollow tile and an outer coating 6 of cement. The top3 for is also provided with a layer 4 of the heat insulatin materialwhich is covered with a layer 6 o cement. At the bottom the dryingchamber in the {present instance is made of square form, an the sidewalls 2 gradually merge to a polygonal form having a greater housing maybe had by means of a stairway 8. At a point approximately centrally ofthe top it is formed with a depression 9' which may be of afrusto-conical form, and

in the bottom wall of the depression an I suitable manner and is provied with any suitable quick-detachable connections with the sprayer 11.

Also disposed on the top 3 is a furnace 14 provided with a burner 15 towhich fuel may be supplied by the pipe 16. leading from the tank 17. Airfor comminuting the fuel may be sup lied to the burner by the pipe 18from eit er of the duplicate blowers 19. The construction of thisfurnace is in general similar to that disclosed in the beforementionedpatent to Bradley & Coflin, but the mixin chamber 20 instead of beingdisposed'at t e side of the furnace is disposed transversely across itstop and is connected to the combustion chamber by the vertical flue 21.An air intake 22 is disposed at one end of the mixing chamber, whichintake is provided with an inlet 23 communicating with the outer air,.and a second inlet 24 communicating with the space within the housing 7.By means of the flap valve 25 the air for drying may be drawn entirelyfrom the outside, entirely from the inside of the housing, or in anydesired roportion from the two. -The mixed com ustion products and airare drawn from the mixing chamber by a suction fan 26 and then conductedthrough the pipe 27 to a centrally disposed manifold 28, provided" witha screen 28', from which manifold lead pipes j 29, in the presentinstance four in number, which are symmetrically disposed around thedepression 9 and lead through the top 3. The ipes 27 and 29 and themanifold 28 may e heat insulated in any suitable manner, and the pipes29 are provided with dampers 30 for regulating the flow of the dryingmedium. It will be seen from Figs.

1' and 2 that the discharge ends of the pipes 29 are provided with anoval flare 31 and that they lead into an annular space defined by thewall of the depression 9 and a circular depending skirt 32. A perforateddiaphragm 33 extends'from the bottom of skirt 32 to the wall ofdepression 9 and between this diaphragm and the outlet 31 of each pipe aperforated oval bafile 34 is disposed.

' downwardly If desired an air distributing means such as shown anddescribed in the above mentioned Bradley & Cofiin patent may besubstituted for the diaphragm 33. Ventilating pipes 35, in the presentinstance two in number, extend upwardly through the top 3 and roof ofhousing 7, said pipes being provided with dampers 36. During operationof the dryer the dampers 36 are closed, but if at any time it is desiredto quickl cool the drying chamber to obtain access t ereto, the

dampers are opened after shutting off the flow of drying air and latex.The space above the depression 9 is in the present embodiment enclosedby a casing 37, and a fan 38 is provided in the wall of said casing formaintaining an air pressure in the casing slightly in excess of that inthe dryin chamber, for a purpose to be later described. Referring toFigs. 5 and '6 it will be seen that a closure 39 is provided for theopening 10, said closure being formed of two overlapping semi-circularhalves 40, which halves are provided with extensions 41 having at theirends intermeshing se mental gears 42, said gears being rigi y connectedto shafts 43 and 44- journalled in a supporting bracket 45. The shaft 44is extended upwardly through the bottom wall of depression 9 and at itsupper end is operatively connected by the intermeshing gears 46 to ashaft 47 extending above the top 3, this latter shaft being actuated bymeans of a hand wheel 48. p

The following mechanism is provided for the ready interchange of thesprayer unit for purposes of inspection, repair, etc. The upper end ofthe sprayer unit is provided with an eye 49 to which a cable 50 may beattached, this cable leading over a pulley 51 mounted in the movablecarriage 52, the cable then extending over a pulley 53 carried by thewall of the casing 37 and thence 52 is provided with rollers 55 movableon to a winch 54. The carriage the angle irons 56 enclosing thecarriage,

which angle irons extend across the casing" 37 and may be supported inits walls or in any other suitable manner. At a point centrally abovethe sprayer when in operative position one of the angle irons 56 isprovided with a recess 57, with which a spring pressed detent 58 mountedon the carriage 52, is adapted to engage, and this detent may bewithdrawn from the recess by the cord 59. Depending from the carriage 52are spaced spring arms 60 on the lower ends of which are mounted lugs ordetents 61,

which latter are adapted to enter the tapering grooves 62 formed onopposite sides of the circular casing head of the s rayer 11.

Adjacent its bottom the drying chamber is provided in the walls 2 withopposed exhaust openings 63 (Fig. 3) for the drying.

medium, which openings extend entirely aaaaoao from one side to theother, hinged adjustable flaps 63 being provided for varying their size.In the present instance these openings also are utilized as an inlet andoutlet for a movable dried latex collecting platform designatedgenerally by the numeral 64. This device in the embodiment shownconsists of a series of platform sections 65 of relatively small lengthbut substantially equal in width to that of the bottom of the dryingchamber (Figs. 3 and 4). Each section is provided with a dependingflexible bafie or skirt 65, which may be made of any suitable materialsuch as canvas, for a purpose to be later described. A sufficient numberof platform sections 65 is used to extend entirely through the dryingchamber and into the exhaust and collecting means at each end, thusforming a continuous collecting surface. The sections may be connectedby any suitable quick-detachable connection, and in the present instancelinks 66 are provided which engage adjacent openings 67 in the sections65. Each section is provided with a suitable number of casters 68 forsupporting it and they may be also provided with the end castors 69(Fig. 1) hearing against the side walls of the drying chamber to preventbinding. Any suitable means may be provided for moving the platformsections through the drying chamber, and in Fig. 4 a pair of fluidoperated cylinders 70 are shown at the inlet end, the pistons of whichmay be provided with rams 71 for actuating the sections. llnstead ofthis a similar pair of cylinders 72 may be mounted at the outlet end ofthe drying chamber and the pistons 73 of the cylinder connected to theforward section by hooks in such manner as to pull the sections throu hthe chamber, or both sets of operating mec anisms may be used. .Forconvenience the cylinders may be pivotally mounted as shown in Fig. 1 sothatd they may be swung to one side when des1re It is desirable that theexhaust drying medium be maintained in contact with the latex collectinplatform sections as long as possible, and t at a circuitous exhaustpassage be provided, in order to prevent any appreciable amount of thedried latex from being carried away in the exhaust gases, and for thispurpose the following exhaust and collecting mechanism is provided. Acover plate 74 is pivotally mounted at 75 on a supporting bracket 76secured to the wall 2 ad acent the exhaust opening 63, and pivotallyconnected to the end of the cover plate. 74 is an end plate 77 extendingto the floor. A deflecting plate 78 is pivotally mounted'on the bracket76 at 79, and in the position shown in full lines in Fig. 3 the plate 78is substantially parallel to the plate 74, and it-extends rearwardly of1ts pivot to the wall 2 just above the openmg chamber.

63. The outer end of the plate 78 terminates short of the end plate 77and is pivotally connected to the plate 74 by links 80. Side walls 80forming in efiect extensions of the walls 2 of the drying chamber formwith the plates 74 and 77 an enclosed space communicating below theplate 78 with the exhaust opening 63. In the present instance the plates74, 77 and 78 are each formed of six sections joined in any suitablemanner. Cables Slare connected at the one end to the top plate 74 andlead over pulleys mounted on the shaft 83, the other ends of the cordsbeing connected to counterweights 84, and it will be seen that by thisconstruction the exhaust device may be swung upwardly When desired, fora purpose to be later explained. The pulleys 82 may be loosely mountedon shaft 83 in which case the exhaust device may be directly lifted byhand, or if desired the pulleys may be rigidly secured to the shaft andthe latter rotated by power to raise the exhaust device. Secured to thebrackets 76 is a wall 85, which may be formed of any suitable material,this wall being spaced from the wall 2 of the drying chamber to form anexhaust flue 86 communicating at its lower endivith the'space below thecover plate 74 and at its uper end with the outlets 87 leading to theopen air, these outlets being controlled by dampers 87 The entireexhaust and collecting mechanism above described is duplicated at theopposite exhaust opening 63 of the drying chamber.

In operation the sprayer 11 is positioned in the opening 10 and suitablyconnected with the latex tank 13. The furnace 14 is then started, thecombustion products being at first allowed to exhaust to the open airthrough the inlet 23 in the manner described in the above-mentionedBradley & Coflin patent. After the furnace has become heated mixedcombustion products and air are then drawn by the fan 26 from the mixingchamber 20 and supplied through the pipe 27, manifold 28, and pipes 29to the dryin The Screen 28' prevents solid particles from passing intothe drying chamber. Any irregularity in the distribution of the dryingmedium may be corrected by means of the dampers 30, and as the dryingmedium passes through the flared outlets 31 of the pipes 29 it is spreadout and is then evenly distributed around the depression 9 by means ofthe perforated baflles 34.

It then passes through the diaphragm 33,,

so that a uniformly distributed slowly moving current of the heateddrying medium flows downwardly into the drying chamber around thesprayer 11. The sprayer 11 is put in operation in a manner similar tothat described in the before-mentioned Bradley & Collin patent, and thesprayed latex is uniformly distributed in the downwardly moving currentof the drying medium as a series of relatively uniform sized particles.The drying medium may be supplied at a relatively'high temperature, asthe latex particles while in the upper part of the drying chamber stillcontain water and hence remain at a temperature around or below 212 F.As the particles approach the bottom in adried condition the temperatureof the gases has been so greatly reduced that there is no longer anydanger of injury to the particles by burning or overheating. Theparticles fall on theplatform sections 65 and the exhaust drying gasesthen pass out through the openings 63 into the exhaust and collectingdevices. The adjustable hinged flaps 63 cause the outgoing gases tosweep directly over the collecting platform 64:. it will be noted thatdue to the extended area of contact furnished by the platform sections65 both in the drying chamber and within the exhaust and collectingdevices substantially all of the latex particles are abstracted from thegases before leaving the collecting platform. The gases then flow uparound the ends of plates 78 and between said plates and the plates 74,and finally upwardly through the fines 86 to the outlets 87. After thedrying operation has continued until the desired quantity of dried latexhas accumulated on the platform sections 65 the exhaust andcollectingdevice is swung upwardly to expose the forward end section 65in the manner shown by the dotted lines in Fig. 3. It will be noted thatwhen in this. position the rear end of the plate 78 extends downwardlyinto contact with the upper surface of the dried latex 88 and thereforethe flow of the exhaust gases outwardly across the forward platformsection 65 is prevented, the ases moving directly up into the flue 86. Ience the operatives can disconnect the forward platform section 65without suffering any inconvenience due to the heat, and the dried latexmay be removed from this section and compacted to form crude rubber orotherwise disposedof, while the empty. platform section may be thenreturned to the opposite side of the drying chamber. The ex haust andcollecting device is then lowered to the full line position of Fig. 3and the exhaust gases resume their former path to the outlet. Theexhaust and collecting device at the opposite end of the drying chamheris previously raised, an empty platform section 65 added on theprecedingone and the rams 71 operated to move the entire 001- lectingplatform 64 a limited distance through the drying chamber, preferablythe length of a single platform section. In-

A stead of operating in the manner just described the bottom of the endplate 77 at the inlet side for the platform sections 65 may be cutawayjust sufliciently to allow entrance of a section, and each section asintroduced partially pushed through so as to form a. seal for theopening. By operating in this manner it will be unnecessary tomanipulate the exhaust and collecting device at this side of the dryerwhile working. As before stated. if desired the collecting platform 64may be pulledthrough by the cylinders 72 and pistons 73, or both thepushing and pulling devices may be used if desired. Any other suitablemeans for moving the collecting platform through the drying chamber maybe substituted. The operation of the drier above described is thencarried on as before, a full platform section being removed at intervalsfrom one end while an empty one is added at the other end. It will beseen that by this construction and mode of operation an integrateddeposit of the dried latex is obtained, since each section moves step bystep from the exhaust and collecting device at one side through thedrying chamber and the exhaust and collecting device at the other side.By reason of the construction and mode of operation previously describedit is apparent that the dryer may be operated continuously and henceworked to its full capacity. I owever, it may be necessary at intervalsto withdraw the spraying unit for repair, inspection, or for otherpurposes,

and in order to prevent shut down of the drier for any length of time itis desirable that this withdrawal be accomplished as quickly as possibleand a duplicate spray- 1 ing unit immediately substituted. When itbecomes necessary to exchange the spraying unit the winch 54 is operatedto draw up the sprayer 11 by means of the cable 50. Asthe carriage 52 isheld stationary by means of the detent 58 the sprayer 11 is drawnstraight up until finally its rounded upper end passes between thedetents 61, thus forcing apart the spring arms 60 until the detents comeopposite the grooves 62, 1 when the detents 61 snap into the grooves andfurther upward movement of the sprayer is prevented. The cable 50 isprovided with a washer 50' which at this time engages the carriage -52to act as a stop and revent undue strain on the detents 61. he cord '59is then operated to withdraw the detent 58 on the carriage 52, and itwill be seen that upon the continued operation of the winch 54 thesprayer and carriage are both moved 1 to one side of the depression 9 tothe position shown in dotted lines in Fig. 5. The sprayer may then bedisengaged from the detent 61 either by directly forcing apart thespring arms 60, or by partially rotating 1 the sprayer to cause thedetents 61 to ride out of the grooves 62. A duplicate sprayer may thenbe attached and lowered to position in place of the other. Any othersuitable means for exchanging the sprayer unit 1 ma ose I! mayl beprovided. Owing to the relatively hig temperature of the drying gasesflowing into the chamber around the depression 9 it will be seen thatwhen the sprayer 11 is first moved off its seat around the opening 10the highly heated gases would tend to flow up into the housing 7,thereby rendering it practically impossible for the operatives to attendto their duties, but by the provision of the casing 37 and the fan 38 aslight excess pressure is maintained within the casing 37, therebypreventing the upward flow of the drying gases. As it is of coursenecessary for the operatives to enter and leave the casing 37 atintervals it will be seen that if it shouldbe desired to do this whilethe opening 10 was free the excess pressure would be at once releasedand the heated drying gases could flow up. To obviate this ditlicultythe closure 39 has also been provided, and as soon as the lower end ofthe spraying unit has passed above the opening 10 the hand wheel 48 maybe operated to move the semi-circular halves 40 together therebymechanically closing the opening 10. After this has been done theoperators may leave and enter the "casing 37 at will. If desired thecasing 37 may be omitted and the air in housing 7 maintained underpressure by a fan.

In the-above-mentioned patent to Bradley & Coflin the drying chamber hasbeen shown as frusto-conical in form. The taper of the side wall fromtop to bottom aids in preventing deposition of dried latex on the walland also owing to its increasing cross sectional area the speed of thedrying medium, which is relatively slow at its entrance, is stillfurther reduced, thereby aiding in the complete deposition of the driedlatex on the floor. As the comminuted latex is discharged into thedrying medium ,in approximately a circular form it is evident thattheoretically the cross sectional form for the drying chamber shouldalso be circular, as this avoids waste of the drying medium which. wouldoccur for instance if the drying chamber were made square, as in thelatter case the spaces at the corners would receive practically nocomminuted latex and those portions of the drying meg dium passingdownwardly in the corners would therefore be ineffective. In additionthe square corners tend to cause eddies, with resultant deposition ofthe dried latex on the side wall. However, after the comminuted latexand drying medium have assed downward some distance in the rying chamberthe drying is substantially completed, and therefore a circular shapefor the lower portion of the drying chamber is not so essential. In thepresent instance the drying chamber has been made of square shape at itsbottom since this allows the movable latex collecting surface to be of atransverse width equal to that of the drying chamber, and italso permitsthe exhaust openings, through which in the present instance the latexcollecting surface also moves, to be made of the full width of thedrying chamber. At the same time it permits'the two walls at the sidesof the openings to be madeof such strength as to adequately support theweight of the entire drying apparatus, which is considerable. For thereasons above pointed out, however, it is still desirable that the upperportion of the drying chamber be made circular or approximately so, andtherefore in the present instance this portion has been made ofoctagonal shape, as such a shape merges very readily into the squareshape of the bottom of the chamber, while at the same time allowing thechamber to be tapered from its top to its bottom. It is obvious,however, that the top portion of the drying chamber need' notnecessarily be octagonal but maybe made circular if desired, or of anyother polygonal shape having a number of sides greater than that of thebottom. It is found, however, that the octagonal shape selected issufficiently close to that o'f'a circle to obtain all of the advantagespointed out in the before-mentioned Bradley & Coffin patent. This formalso readily lends itself to the beam construction of the top and thelocation of the depression 9.

lVhile it is obvious that the openings 63 may be used solely for theinlet and exit of the latex collecting platform sections, and theexhaust openings for the drying medium disposed in t e side walls, theconstruction shown allows the side walls to be made of maximum strengthto support the heavy Weight of the drying apparatus, and by using theopenings 63 for the inlet and exit ofthe sections they are exposed forthe maximum length of time to the dryin medium before the latter passesto the ex aust fines, and every portion of the collecting platform fromthe moment a new section is added until the time that a full section isremoved is in unobstructed contact with the drying medium. By theprovision of the flaps 65' any tendency of the exhaust es to pass aroundthe small gaps at the sides of the latform and then outwardly beneaththe p atform is prevented. It will be seen that by reason of the exhaustand collecting devices the exhaust gases are never allowed to passdirectly into the outside air but are furnished with a circuitous pathto obtain a maximum recovery of the dried latex particles. Owing to thearrangement shown, however, the recovery of the latex particles on theplatform 64 1s so thorough that only a minimum amount is carried beyondthem, and the exhaust and collecting devices need therefore to becleaned only at relatively long intervals.

It will also be seen that when the exhaust and collecting devices areraised the opera- 3 in cases Where the drier is located in tropi-- calcountries. By the provision of the air intake 22, however, all or anyportion of the air within the housing 7 may be drawn into the mixingchamber 20 of the furnace and fresh air drawn in through the windows orother openings of the housing 7 to take the place of the heated air.Also by reason of this constructionand the direct air heating a maximumproduction of drying medium is obtained.

While a specific embodiment of the invention has been shown anddescribed it is obvious that numerous modifications will suggestthemselves to those skilled in the art and it isnot desired to limit theinvention otherwise than as set forth in the appended claims.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

1. In an apparatus for drving latex and similar material, a dryingcamber, means for supplying comminuted latex and a drymg medium thereto,and means movable through the chamber for obtaining an integrateddeposit of the dried latex.

2. In an apparatus for drying latex and similar material, a dryingchamber. means for supplying comminuted latex and a dry ing mediumthereto, and removably con nected sectionalf means for obtaining anintegrated deposit of the dried latex.

3. In an apparatus for dr 'ing latex and similar material, a drying camber, means for sup lying comminuted latexand a drying me ium thereto,removably connected sectional means ex osed at all points to said mediumfor obtaining an. integrated de sit of the dried latex, and means wherey a section may be cut off from such exposure for withdrawal.

4. In an apparatus for drying latex and similar material, a dryingchamber, means for supplying comminutedlatex and a drying m ium thereto,and a dried latex collecting surface movable through said chamher anduninterruptedly exposed therein to the current of the medium carryingthe dried particles.

5. In an apparatus for drying latex and similar material, a dryinchamber, means for supplying coniminu latex and a drying medium adjacentone end thereof, means adjacent the opposite end for exhausting saidmedium, and a movable dried latex collecting surface extending throughsaid chamber and exhaust means.

6. In an apparatus for drying latex and similar material, a dryingchamber, means for sup lying comminuted latex and a drying mediumadjacent one end thereof, opposed exhaust passages adjacent the otherend, and a movable dried latex collecting surface extending through saidchamber and assages.

7 In an apparatus for drying latex and similar material, an unobstructeddrying chamber, means for supplying comminuted latex and a drying mediumadjacent one end thereof, opposed exhaust openings adjacent the otherend, and a movable sectional dried latex collecting surface extendingentirely across said chamber and through said openm i In an apparatusfor drying latex and similar material, a drying chamber, means forsupplying comminuted latex and a drying medium adjacent one end thereof,a circultous exhaust passage communicating with the other end, a movabledried latex collecting surface extending through said chamber andpassage, and means for short circuiting said passage when desired.

9. In an apparatus for drying latex and similar material, a dryingchamber. means for supplying comminuted latex and a drying mediumadjacent one end thereof, a dried latex collecting surface extendingbeyond the drying chamber, and means for varying the operative extent ofsaid surface.

10. In an apparatus for drying latex and similar material, a dryingchamber. means for supplying comminuted latex and a drying mediumadjacent one end thereof. a dried latex collecting surface movablethrough and outside of said chamber, and movable means for alternativelyconducting the exhaust from said chamber across or away from the portionof said surface outside the chamber.

11. In an apparatus for drying latex and similar material, a dryingchamber. means for supplying comminuted latex and a drying mediumadjacent one end thereof, an exhaust opening adjacent the other end, amovable dried latex collecting surface adapted to extend through saidchamber and through andoutside said opening, and means for at willdeflecting the exhaust over or away from said outside portion of thecollecting surface.

12. In an apparatus for drying latex and similar material, a dryinchamber. means for supplying comminute latex and a drying 111 'umadjacent one end thereof, an

Ill

carat exhaust opening adjacent the other end, a movable dried latexcollecting surface adapted to extend through said chamber and throughand beyond said opening, a cover for the portion of said surfaceextending across said chamber adjacent its larger en 14. In a dryingapparatus, atapering drying chamber of polygonal form at its base andmerging into a polygon of a greater number of sides at its top and meansmovable across the base for collecting dried material.

15. In a drying apparatus, a tapering drying chamber of square form atits base, with side walls approaching a circular form at the top andmeans movable across the base for collecting dried material.

16. Ina drying apparatus, a tapering drying chamber of square form atits base, with side walls approaching a circular form at the top, andopposed exhaust openings at the %ase extending the full -width of thecham- 17. In a drying apparatus, a tapering drying chamber of polygonalform at its base and approaching a circular form at its top, means forsupplying comminuted latex and a drying medium thereto, opposed exhaustopenings adjacent the base, and dried latex collecting means movablethrough said chamber in unobstructed contact with the drying medium.

18. In an apparatus for drying latex and similar material, a dryingchamber, means adjacent its top for distributing finely divided latexlaterally thereinto, a supply duct for a drying medium, a manifoldconnected thereto, and downwardly directed ducts leading from saidmanifold into the top of the drying chamber at symmetricallyspacedpoints around said latex distributing means.

19. In an apparatus for dryin latex and similar material, a drying chamer, means for supplying comminuted latex ad acent the top thereof asupply duct for adrying medium, a manifold connected thereto$ductsleading from said manifold through the top of the drying chamber atsymmetrically spaced points around said latex supply means, said ductshaving enlarged outlets, and valves controlling the flow through saidlast named ducts.

20. In an apparatus for drying latex and similar material, a dryingchamber, means for supplying latex thereto, means forming an enc osedspace adjacent said drying chamber, a heating furnace for a dryingmedium disposed in said space, means for conducting the heated mediumtherefrom to the drying chamber, and means for at will supplying thedrying medium to said furnace from within or without said space or both.

21. In an apparatus for drying latex and similar material, adryingchamber, means for comminuting latex therein, means forming anenclosed space above said drying chamber, an air heating furnacedisposed in said space, means for conducting heated air therefrom to thedryingchamber, and means for .at will supplying air to said furnace fromwithin or without said space or both.

22. In an apparatus for dryinglatex and similar material, a dryingchamber, means for su plying latex thereto, means forming an enc osedspace above said chamber, an air heating furnace disposed in said space,means disposed in said space for conducting heated air. from the furnaceto symmetrically spaced points in the drying chamber, and means forsupplying air to said furnace from within or without said space or both.

23. In an apparatus for drying latex and similar material. a dryingchamber, means for supplying latex thereto, means forming with the wallof said drying chamber an enclosed space, an air heating furnace dis--posed in said space, means for conducting heated air therefrom to thedrying chamber, an an supply duct leading tosaid furnace and havingopenings communicating with said space and with the outside air, and ayalve in said duct for controlling said openlugs.

24. In an apparatus for drying latex and similar material. a dryingchamber, means for supplying latex thereto, symmetrically Spaced meansfor supplying a drying medium thereto. and a baflie disposed in spacedrelation to each of said last named supply means.

.25. In an apparatus for drying latex and similar material, a dryingchamber, means for commi'nuting and uniformly distributing latextherein, means for supplying a drying medium to the chamber atsymmetrically spaced points around said first means, and

means in the chamber for uniformly distributing the drying medium to thecomminuted latex.

26. In an apparatus for dryin latex and similar material a dryingchaniber having an aperture in its top wall,- a readily removablespraying unit disposed in said aperture with its discharge end in saiddrying chamher, a series of supply pipes for a drying vmedium havingoutlets to said chamber 1n spaced relation tothe spraying unit, and

means for uniformly distributing the discharge from said pipes.

27. In an apparatus for drying latex and similar material, a dryinchamber having a central inwardly projecting apertured well in its topwall, a latex spraying device removably mounted in said aperture, meansfor discharging a drying medium at symmetrically spaced points aroundsaid device,

and means surrounding said last means for uniformly distributing anddirecting the medium to the sprayed latex.

28. In an apparatus for drying latex and similar material, a dryingchamber, means adjacent the top thereof for supplying comminuted latexand a drying medium, means adjacent the bottom whereby said medium maybe exhausted, and regulable means for causing a reverse draft throughsaid chamber when desired.

29. In an apparatus for dryin latex and similar material, a drying chamer, means adjacent the top thereof for supplying comminuted latex and adrying medium, means adjacent the bottom whereby said medium may beexhausted. and damper controlled ventilating stacks leading into theupper portion of said chamber.

30. ha drying apparatus. a drying chamher having anopening in the wallthereof, means whereby a distributor for the material to be dried may beinterchangeably mounted in and close the opening, means for supplying adrying medium to the chamber, and means for preventing egress of saidmedium throughthe opening during an interchange of distributors.

31. In a drying apparatus, a drying chamber having an opening in itstop, asprayer for the material to be dried removably disposed in andclosin said openin means for supplying a heate drying me ium to thechamber, and means operating by, fluid pres sure for preventing egressof said medium through the opening upon removal of the sprayer.

32. In a drying apparatus, a drying chamueaoao ber having an opening inits top, a. 3 re er for the material to be dried removab y isposed inand closing said opening, means for at will exchanging said sprayer foranother, means for supplying a. heated drying medium to the chamber, andmeans for projecting an air current downwardl through said opening toprevent egress c said me dium through the opening during an interchangeof sprayer-s.

33. In a drying apparatus,a drying chamber having an aperturedde ressionin its top, a sprayer for the materlal to be dried removab y disposed inand closing said aperture, means for supplying a heated drying medium tothe chamber, and means operable from the top for mechanically closingthe aperture after removal of the sprayer.

34. In a drying apparatus, a drying chamber having a depression in itstop with an opening at the bottom of the depression, a sprayer for thematerial to be dried remova ly disposed in and closing said opening,means for supplying a heated drying medium to the chamber, a casingenclosing the space above said depression, means for maintaining an airpressure therein in excess of that in the drylng chamber, and means formechanicall closing the opening upon withdrawal of t e sprayer.

35. In a drying apparatus, a drying chamber, means for supplyingcomminuted latex and a drying medium thereto, dried latex collectingmeans movable through said' chamber, and means for preventing escape ofthe drying medium beneath said collectmg means.

36. In a drying ap aratus', a drying chamber, means for supp yingcomminuted latex and a. drying medium thereto, dried latex collectingmeans movable through said chamber abovethe floor thereof, and flapsextendin from said last means to the floor.

Signe at New York city, county of New York, and State of New York, this26th day of April, 1923.

JOSEPH G. COFFIN.

